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// Functions used by iterators -*- C++ -*- |
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// Copyright (C) 2001-2013 Free Software Foundation, Inc. |
// |
// This file is part of the GNU ISO C++ Library. This library is free |
// software; you can redistribute it and/or modify it under the |
// terms of the GNU General Public License as published by the |
// Free Software Foundation; either version 3, or (at your option) |
// any later version. |
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// This library is distributed in the hope that it will be useful, |
// but WITHOUT ANY WARRANTY; without even the implied warranty of |
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
// GNU General Public License for more details. |
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// Under Section 7 of GPL version 3, you are granted additional |
// permissions described in the GCC Runtime Library Exception, version |
// 3.1, as published by the Free Software Foundation. |
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// You should have received a copy of the GNU General Public License and |
// a copy of the GCC Runtime Library Exception along with this program; |
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
// <http://www.gnu.org/licenses/>. |
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/* |
* |
* Copyright (c) 1994 |
* Hewlett-Packard Company |
* |
* Permission to use, copy, modify, distribute and sell this software |
* and its documentation for any purpose is hereby granted without fee, |
* provided that the above copyright notice appear in all copies and |
* that both that copyright notice and this permission notice appear |
* in supporting documentation. Hewlett-Packard Company makes no |
* representations about the suitability of this software for any |
* purpose. It is provided "as is" without express or implied warranty. |
* |
* |
* Copyright (c) 1996-1998 |
* Silicon Graphics Computer Systems, Inc. |
* |
* Permission to use, copy, modify, distribute and sell this software |
* and its documentation for any purpose is hereby granted without fee, |
* provided that the above copyright notice appear in all copies and |
* that both that copyright notice and this permission notice appear |
* in supporting documentation. Silicon Graphics makes no |
* representations about the suitability of this software for any |
* purpose. It is provided "as is" without express or implied warranty. |
*/ |
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/** @file bits/stl_iterator_base_funcs.h |
* This is an internal header file, included by other library headers. |
* Do not attempt to use it directly. @headername{iterator} |
* |
* This file contains all of the general iterator-related utility |
* functions, such as distance() and advance(). |
*/ |
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#ifndef _STL_ITERATOR_BASE_FUNCS_H |
#define _STL_ITERATOR_BASE_FUNCS_H 1 |
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#pragma GCC system_header |
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#include <bits/concept_check.h> |
#include <debug/debug.h> |
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namespace std _GLIBCXX_VISIBILITY(default) |
{ |
_GLIBCXX_BEGIN_NAMESPACE_VERSION |
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template<typename _InputIterator> |
inline typename iterator_traits<_InputIterator>::difference_type |
__distance(_InputIterator __first, _InputIterator __last, |
input_iterator_tag) |
{ |
// concept requirements |
__glibcxx_function_requires(_InputIteratorConcept<_InputIterator>) |
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typename iterator_traits<_InputIterator>::difference_type __n = 0; |
while (__first != __last) |
{ |
++__first; |
++__n; |
} |
return __n; |
} |
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template<typename _RandomAccessIterator> |
inline typename iterator_traits<_RandomAccessIterator>::difference_type |
__distance(_RandomAccessIterator __first, _RandomAccessIterator __last, |
random_access_iterator_tag) |
{ |
// concept requirements |
__glibcxx_function_requires(_RandomAccessIteratorConcept< |
_RandomAccessIterator>) |
return __last - __first; |
} |
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/** |
* @brief A generalization of pointer arithmetic. |
* @param __first An input iterator. |
* @param __last An input iterator. |
* @return The distance between them. |
* |
* Returns @c n such that __first + n == __last. This requires |
* that @p __last must be reachable from @p __first. Note that @c |
* n may be negative. |
* |
* For random access iterators, this uses their @c + and @c - operations |
* and are constant time. For other %iterator classes they are linear time. |
*/ |
template<typename _InputIterator> |
inline typename iterator_traits<_InputIterator>::difference_type |
distance(_InputIterator __first, _InputIterator __last) |
{ |
// concept requirements -- taken care of in __distance |
return std::__distance(__first, __last, |
std::__iterator_category(__first)); |
} |
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template<typename _InputIterator, typename _Distance> |
inline void |
__advance(_InputIterator& __i, _Distance __n, input_iterator_tag) |
{ |
// concept requirements |
__glibcxx_function_requires(_InputIteratorConcept<_InputIterator>) |
_GLIBCXX_DEBUG_ASSERT(__n >= 0); |
while (__n--) |
++__i; |
} |
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template<typename _BidirectionalIterator, typename _Distance> |
inline void |
__advance(_BidirectionalIterator& __i, _Distance __n, |
bidirectional_iterator_tag) |
{ |
// concept requirements |
__glibcxx_function_requires(_BidirectionalIteratorConcept< |
_BidirectionalIterator>) |
if (__n > 0) |
while (__n--) |
++__i; |
else |
while (__n++) |
--__i; |
} |
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template<typename _RandomAccessIterator, typename _Distance> |
inline void |
__advance(_RandomAccessIterator& __i, _Distance __n, |
random_access_iterator_tag) |
{ |
// concept requirements |
__glibcxx_function_requires(_RandomAccessIteratorConcept< |
_RandomAccessIterator>) |
__i += __n; |
} |
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/** |
* @brief A generalization of pointer arithmetic. |
* @param __i An input iterator. |
* @param __n The @a delta by which to change @p __i. |
* @return Nothing. |
* |
* This increments @p i by @p n. For bidirectional and random access |
* iterators, @p __n may be negative, in which case @p __i is decremented. |
* |
* For random access iterators, this uses their @c + and @c - operations |
* and are constant time. For other %iterator classes they are linear time. |
*/ |
template<typename _InputIterator, typename _Distance> |
inline void |
advance(_InputIterator& __i, _Distance __n) |
{ |
// concept requirements -- taken care of in __advance |
typename iterator_traits<_InputIterator>::difference_type __d = __n; |
std::__advance(__i, __d, std::__iterator_category(__i)); |
} |
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#if __cplusplus >= 201103L |
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template<typename _ForwardIterator> |
inline _ForwardIterator |
next(_ForwardIterator __x, typename |
iterator_traits<_ForwardIterator>::difference_type __n = 1) |
{ |
std::advance(__x, __n); |
return __x; |
} |
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template<typename _BidirectionalIterator> |
inline _BidirectionalIterator |
prev(_BidirectionalIterator __x, typename |
iterator_traits<_BidirectionalIterator>::difference_type __n = 1) |
{ |
std::advance(__x, -__n); |
return __x; |
} |
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#endif // C++11 |
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_GLIBCXX_END_NAMESPACE_VERSION |
} // namespace |
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#endif /* _STL_ITERATOR_BASE_FUNCS_H */ |